ENDOCRINE ORGANS AND RESPIRATORY SYSTEM
RESPIRATORY SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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expanding with air
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shrinking
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Either A or B
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None of the above
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Detailed explanation-1: -Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and air is forced out of the lungs.
Detailed explanation-2: -During inspiration, the diaphragm contracts and the thoracic cavity increases in volume. This decreases the intraalveolar pressure so that air flows into the lungs. Inspiration draws air into the lungs.
Detailed explanation-3: -Relaxation of the diaphragm causes the rib cage to move closer to the lungs leading to an increase in intrapleural pressure back to-5 cm H2o. As a result, lung volume decreases, and pressure becomes higher than atmospheric pressure.